Re: [PATCH] Prevent out-of-bounds read/write in bcmasp_netfilt_rd and bcmasp_netfilt_wr

[Yuran Pereira]

Hello Greg,
On Fri, Nov 03, 2023 at 01:57:13PM +0100, Greg KH wrote:
> >  	reg_offset = bcmasp_netfilt_get_reg_offset(priv, nfilt, reg_type,
> >  						   offset);
> > +	if (reg_offset < 0)
> > +		return 0;
> 
> Shouldn't you return an error here?

Yes, I think that makes sense. I might just return `reg_offset`
since it is bound to be -EINVAL when bcmasp_netfilt_get_reg_offset
fails.

But that now makes me wonder whether the previous check in that
function which currently returns 0, shouldn't be returning `-EINVAL`
instead.

```
static u32 bcmasp_netfilt_rd(struct bcmasp_priv *priv,
...
{
	if (!IS_ALIGNED(offset, 4) || offset > MAX_WAKE_FILTER_SIZE)
		return 0;   <----- Should this one be -EINVAL?
}
```

Thank you for the feedback.

Yuran